This invention relates to X-ray apparatus, and more particularly, to a compact, lightweight and portable X-ray apparatus.
The conditions for a portable X-ray apparatus require that the apparatus be relatively small, light and in an external form convenient for carrying.
Referring to FIG. 1, a conventional portable X-ray apparatus includes a cylindrical casing 14 containing an X-ray tube 10 and a high voltage transformer 11 and 12, the casing being filled with an insulating oil 13. The external form of the casing 14 is cylindrical for carrying, but the apparatus is very heavy due to the weight of the insulating oil 13.
To reduce this weight it is known to fill the casing 14 with sulfur hexafluoride (SF6) gas as a substitute for the insulating oil. However, the heat produced from the X-ray tube and the X-rays emitted from the X-ray tube themselves tend to lower the insulation ability of the SF6 gas, especially in high output X-ray apparatus. In another portable X-ray apparatus, shown in FIG. 2, an X-ray tube 20 is contained in a casing 23 which is filled with an insulating oil 21. A high voltage transformer 24, a rectifier 25, a protective resistor 26 and a filament transformer 27 compose a high voltage section 28. The components of the high voltage section 28 are contained in a casing 29 which is filled with an SF6 gas 30. These two casings 23 and 29 are connected to each other electrically and mechanically by bushings 31 and 31. The insulating oil is stored in a tank 32 and is introduced into the casing 23 by circulation pipes 33. Accordingly, the X-rays are not emitted in the region filled with the SF6 gas.
This apparatus is lighter than that shown in FIG. 1 and has a feature that the deterioration of the insulation ability of the SF6 gas is avoided. However, the apparatus shown in FIG. 2 is not always portable for the reason that the casings 23 and 29 are stacked one on the other and the tank 32 is connected to the casing 23. This apparatus, therefore, becomes heavier and more awkward to handle than the apparatus filled only with SF6 gas.